Floodplain conservation in the Mississippi River Valley: combining spatial analysis, landowner outreach, and market assessment to enhance land protection for the Atchafalaya River Basin, Louisiana, U.S.A.

Abstract

Threats to riverine landscapes are often the result of system-wide river management policy, located far from where the threats appear, or both. As a result, the rationale for land protection to achieve floodplain conservation and restoration has shifted to require that lands must also have multiple and systemic threat abatement benefits. The Mississippi River Flood of 2011 highlighted the need for increased floodplain complexes along the Mississippi River to provide both systemic threat abatement and conservation benefits. We used spatial analysis, landowner outreach, and market assessment to examine ways to enhance land protection in the Atchafalaya River Basin Floodway, the largest river basin swamp North America and the site of two employed floodway locations during the 2011 flood. We identified six Priority Conservation Areas (77,084 ha) in the floodway that are largely privately owned (mean 78.2 ± 6.4%), with forest dominated by Taxodium distichum (baldcypress) and hydrologic and water quality characteristics considered most suitable for baldcypress regeneration (31.2 ± 2.4% and 10.2 ± 3.0% of area, respectively). Landowners expressed high (80%) interest in land protection programs and found the range of property values derived from market analyzes (minimal protection-$346 USD/ha; additional protections-up to $2,223 USD/ha) to be reasonable. We seek to: (1) enhance current land protection in the Atchafalaya River Basin and (2) provide a model for using land protection to increase the number of floodplains for both systemic threat abatement and conservation benefits. Implications for Practice• These results provide a model for rapid development and implementation of land conservation with public and private funding throughout the Mississippi River system to (1) achieve system-wide benefits (i.e. flood protection) and (2) protect biodiversity, and (3) advance conservation. • We provide a model to engage decision-makers and landowners, garner stakeholder support, and procure funding to achieve land protection in key floodplain areas.

Using Flow-Ecology Relationships to Evaluate Ecosystem Service Trade-Offs and Complementarities in the Nation’s Largest River Swamp

“…Despite the federally-mandated flow regime, there appears to be considerable flexibility in daily and seasonal releases that could allow flow experiments without significant legal entanglements (Online Resource 1). Additionally, water management in the ARB is unique in that ORCC creates a semi-natural flow regime that generally mimics seasonality of the Lower Mississippi River but limits extreme flow variability (Piazza 2014;Piazza et al 2014). This characteristic contrasts with infrastructure such as hydropower dams, which generally disrupt seasonality, and the difference could be useful in comparing responses to wholesale flow regime changes (e.g., the Colorado River) versus adding high and low flow extremes to an otherwise intact seasonal flow pattern.…”

“…The ARB provides many ecosystem services valued in the billions of dollars annually (Piazza 2014). Provisioning services provide direct goods and are the most wellknown in the ARB.…”

Landscape Scale Assessment of Floodplain Inundation Frequency Using Landsat Imagery

“…Results and products from these data may be applied to a wide diversity of conservation, research and management applications. In a recent study, Piazza et al (2015) used a similar inundation index approach to define conservation opportunity areas within the Atchafalaya River basin based on the availability of hydrologic patterns suitable for cypress regeneration. Also within the Atchafalaya basin, predicted inundation extent based on Landsat observations was used to establish specific maximum river stage thresholds for LiDAR acquisition.…”

Spatial and temporal patterns in fish community structure and abundance in the largest U.S. river swamp, the Atchafalaya River floodplain, Louisiana

“…Although the ARB is highly managed, it maintains relative seasonal flows that match the Mississippi River and still experiences widespread floodplain inundation (Piazza 2014;Piazza et al 2014). The ARB also has a variety of water quality issues, such as sedimentation of deep-water habitats and severe hypoxia, mostly due to artificial flow paths that create opposing flow directions and prevent flood waters from naturally receding into the main channel during warm summer months (Sabo et al 1999a,b;Kaller et al 2011;Piazza 2014).…”